Project Summary This application is being submitted in response to NOT-DA-19-003. Four out of five youth in the juvenile justice (JJ) system show evidence of being under the influence during their offenses, and over half test positive for substances at the time of their arrest (Hockenberry &. Puzzanchera, 2014). Preventive intervention approaches that can be easily implemented within JJ settings may offer greater access to substance use care as well as increase families? motivation to comply with court referrals to seek further services. It is especially important to evaluate interventions for court-involved, non-incarcerated (CINI) juveniles as these youth account for two-thirds of those arrested (Hockenberry &. Puzzanchera, 2014), but the bulk of extant research has been conducted with detained or incarcerated youth. The parent grant (DA045396-01A1) to this proposed supplement, ?Brief Individual and Parent Interventions for Marijuana Misuse in Truant Adolescents?, is now examining the effects of our experimental intervention with 150 truant, MJ using adolescents recruited from Rhode Island Family Court and Rhode Island Truancy Court. In this application for supplemental funding, we capitalize on our parent grant by proposing to develop an adjunctive, targeted preventive intervention for marijuana-using, JJ youth who are at elevated risk for illicit opioid use. Using an in-depth interview (IDI) design, we will conduct open-ended individual qualitative interviews with a sample of 30-40 older (16 ? 18 years old) adolescent/parent dyads. The goal will be to develop a protocol for a single-session, parent-adolescent preventive intervention to decrease the likelihood of illicit opioid use in CINI adolescents. We will also collate psychoeducational material and introduce potential intervention components, e.g. the use of videos on this topic, to obtain feedback on their potential inclusion in the protocol. Interviews will last approximately 60 minutes, follow a semi-structured interview guide, and be recorded for analysis. Using an iterative approach, we will conduct 2-3 IDIs, balanced on gender in four rounds. After each round, data will be reviewed and the interview agenda adapted as needed for additional information (emergent data; saturated data; prioritizing different questions as the rounds proceed). Key themes will be extracted from the qualitative interviews for analyses to guide intervention development. We will collect additional preliminary information that may inform treatment of adolescents with an opioid use disorder, from the small number of adolescents (approximately 10%) that we anticipate will report a history of illicit opioid use during their qualitative interview. This formative work will culminate in a draft intervention manual. We will then conduct a small open trial of the preventive intervention with 10 CINI adolescents and their parents/guardians.